Hi all new to group so hoping got this in the right section if not I apologise does anyone have a diagram of the wiring going to the connector for the map sensor colours and so on I know there are 4 brass pins but I could do with identifying the earth wire and voltage in other 3 wires thanks in advance

Hi Alun,

Which discovery? D1 or D2? also which engine?

Cheers

You can download the Rave manual including the electrical diagrams here.

Covers a lot of LR products. Rave01 is D2, Rave 03 should be for D1.
http://www.green-oval.com/data/lr/

Cheers

Sorry its the 2.5 td5 discovery 2

The MAP/IAT sensors are combined in one unit located in the inlet manifold. It provides pressure and temperature information about the air in the inlet manifold to the Engine Control Module (ECU). The ECM compares the voltage signal to stored values and compensates fuel delivery as necessary.
There are four wires to the device:

• Pink/Black to pin 1. Circuit 0 volts "earth"
  
• Green/Black to pin 2. IAT output to ECU
  
• Pink/purple to pin 3. +5 volts supply to sensors.
  
• White/yellow to pin 4. MAP output to ECU

The unit contains both the Manifold Absolute Pressure (MAP) and Inlet Air Temperature (IAT) sensors. The IAT uses a negative co-efficient resistor (thermistor) as its sensor while the MAP uses a piezo electric crystal device.
From what I can see there is no "actual" ground in terms of a wire taken directly to a ground terminal, but a "0 volts" line fed from the ECU and common to both MAP and IAT circuits.

That's the information you can get from RAVE, as advised by @neilly